Oak Harbor is a city located upon Whidbey Island in Island County, Washington, United States. The population was 22,075 at the 2010 census. Oak Harbor was incorporated upon May 14, 1915.

Oak Harbor is Whidbey Island’s largest incorporated city; it is named for the Garry Oak trees which grace its skyline. The city’s buildup coincided with two major events: the building of Deception Pass Bridge on July 31, 1935, and the triumph of Naval Air Station Whidbey Island upon September 21, 1942.
Oak Harbor’s archives goes back to the early 1850s, when two settlers staked claims where the city now stands—Zakarias Toftezen, a shoemaker from Norway; C.W. Sumner from New England.

Houses and businesses sprouted occurring along the shores of Oak Harbor as the pioneers relied entirely on water transportation until the 1900s. For the bordering 30 years, steamers and freighters carried passengers and freight from the Island to the mainland and assist as competently as Fidalgo Island to the north.

The Irish came in the late 1850s, making Oak Harbor be credited with and prosper as they fished and farmed the area, and the city’s Dutch extraction arrived in the 1890s. Churches, schools, and more businesses followed the coming on of the Dutch. A high school was built in 1906. Oak Harbor flourished as a small country town until Deception Pass Bridge and the U.S. Navy Base united the city to the ablaze of the region and the world.

Deception Pass Bridge, a National Historic Monument before 1982, is actually two spans that associate Whidbey Island to Fidalgo Island more than Canoe Pass and Deception Pass. The bridge, one of the scenic wonders and destinations of the Pacific Northwest, was a Public Works Administration project built by the Civilian Conservation Corps. Deception Pass State Park has over 4,100 acres (17 km²) of forest, campsites, trails, and scenic vistas of the San Juan Islands, Victoria (British Columbia, Canada), Mount Baker, and Fidalgo Island.